This invention relates to cervical devices, and more specifically, to a cervical drug delivery apparatus having a concave cap attached to the end of a cylindrical structure for applying and delivering therapeutic agents to a patient""s cervix.
Currently, therapeutic agents, e.g. misoprostol, are delivered to a human cervix by either inserting a tablet or gel directly into the vagina, which exposes both the vagina and cervix to the agent, or by direct injection of the agent into the cervix with a needle. The disadvantage with this procedure, however, is that several agents designed for drug therapy to the cervix are either systemically toxic or cause irritation to the vagina or outer vulva. Other agents given for cervical maladies are creams also inserted into the vagina. The disadvantage with creams is that they often leak out onto the vulva and become extremely irritating and painful.
Therefore, a cervical agent delivery apparatus is needed that provides for the direct administration and delivery of therapeutic agents to the cervix, e.g., anesthetics, anti-virals, anti-neoplastics and cervical ripening agents, while minimizing vaginal and systemic exposure to the agent. Since the cervix is not as highly vascularized as the vagina, direct administration to the cervix would reduce systemic exposure since less drug will be distributed to the body and the desired organ will be specifically targeted.
One example of conventional methods of drug delivery to a patient""s cervix involves the administration of anesthetic agents to reduce pain and discomfort prior to cervical dilation or biopsy. Currently, there are no other established methods for administering anesthetic agents to a patient""s cervix other than direct injection of the anesthetic via a needle and syringe. Most patient""s report this injection to be more painful and uncomfortable than the procedure (which itself is uncomfortable and sometimes painful). Thus, the majority of women, and their physicians, choose to forego any anesthetic agent and thus endure the associated pain.
As another example of conventional methods for cervical drug delivery, Misoprostol, a tablet traditionally used to prevent non-steroidal anti-inflammatory drug induced ulcers in a patient""s stomach, is another example of a drug sometimes delivered to the cervix. However, Misoprostol is contra-indicated on its label for use with a pregnant patient because of its effect for inducing labor. In reality, however, physicians often apply misoprostol for its off-label use in the promotion of cervical ripening in pregnancy wherein the physician directly applies a misoprostol tablet to a patient""s cervix in order to induce cervical ripeness, thereby inducing labor. There are many disadvantages with using misoprostol for this off-label use. First, this topical use is directly counter to the drug""s allowed use. Second, the tablet form of misoprostol is intended for oral ingestion onlyxe2x80x94not as a topical agent. Therefore, the tablet form occasionally does not dissolve in a vagina. In addition the tablet may be difficult to position properly so as to directly contact the cervix. Lastly and most importantly, the proper dosage of misoprostol has not been ascertained or even studied because this use of misoprostol is a non-labeled use. Therefore, physicians typically use a xe2x80x9chit or missxe2x80x9d dosage until the desired effect is achieved.
Therefore, there is a need for an alternative form of misoprostol, other than tablet form, that can be easily and removably placed in a patient""s vagina in direct contact with the cervix. Furthermore, there is a need for this alternative form of misoprostol that can be used with a cervical agent delivery apparatus providing the direct application of misoprostol on a patient""s cervix.
Another type of device used in connection with covering a patient""s cervix is the cervical cap. For example, the Prentif Cervical Cap(copyright) covers a patient""s cervix and is used as a barrier method of contraception. Similarly, the Today R contraceptive sponge was a sponge-like device shaped to fit over a patient""s cervix thereby also serving as a physical contraceptive barrier. However, the Today R sponge also contained nonoxynol-9 (a spermicidal agent) which was released into the vagina to assist in preventing contraception. A second type of cervical cap is the Instead(copyright) (cervical) Cap which is a flexible ring connected to a flexible plastic sac-like reservoir. The ring fits around a patient""s cervix wherein the reservoir collects the patient""s menstrual flow. This device is not designed to fit closely around the cervix.
Other types of devices used in connection with a patient""s cervix consist of a catheter that is inserted through the cervix and into the uterus to allow administration of agents to enhance the contrast seen in the uterus during an ultrasound procedure. An example of this type of device is the Zinnanti Uterine Injector R which is a catheter having a cervical stop to prevent inserting it too far into the patient""s uterus. This device is available in 2 and 4 mm sizes, and in dual lumen designs allowing delivery of an agent through one lumen and delivery of air to a balloon-like structure through the second lumen to prevent it from coming out of the uterus.
Therefore, there is a need for a cervical agent delivery apparatus and system for applying and delivering a cervical agent directly to a patient""s cervix. There is a further need for a cervical agent delivery apparatus that allows for the treatment of a patient""s cervix with a therapeutic agent for an undetermined length of time. There is still a further need for a cervical agent delivery apparatus having a means for supporting the apparatus in the proper position over a patient""s cervix.
The apparatus and system of the present invention solves the problems with conventional means for applying and delivering therapeutic cervical agents to a patient""s cervix by providing a flexible or semi-rigid cervical cap made of plastic, rubber or similar material that is attached to a front end of a cylindrical structure of absorbent material, e.g., a tampon, thereby creating a cervical agent delivery apparatus. In operation, a desired therapeutic agent is applied to the internal surface of the cervical cap either prior to shipping, such as by the manufacturer, by hand or by a medicated pad attached to the internal surface of the cervical cap immediately prior to use. Once prepared, medical personnel, or a patient, inserts the apparatus into the patient""s vagina, as in a conventional method for using tampons, wherein the front end with the cervical cap is inserted first. Upon insertion of the apparatus, the cervical cap comes in direct contact with the patient""s cervix due to the natural positioning of the cylindrical structure. Therefore, the therapeutic agent on the internal surface of the cervical cap is dispersed directly to the cervix for treatment. The apparatus is held in place by conventional means, that is, by the anatomy of the vagina surrounding the cylindrical structure. The cylindrical structure protects the spreading of the therapeutic agent to the vagina and vulva due to its inherent absorbency. The cylindrical structure absorbs that portion of the therapeutic agent that leaks out of the cervical cap and/or off of the cervix. The apparatus of the present invention can either be self-administered by a patient for home use, thereby minimizing health care costs, or can be inserted by a physician.
In one alternative embodiment, the cervical agent delivery apparatus of the present invention further comprises a tube applicator as a means for deploying the apparatus, similar to a conventional tampon applicator. In this embodiment, the entire apparatus (the cylindrical structure and the cervical cap with the cervical agent previously applied) are housed within the applicator wherein the cervical cap is compressed such that it fits within an internal chamber of the applicator. This alternative apparatus is deployed using conventional methods for deploying a tampon. Therefore, upon deployment, the cervical cap opens to its intended form and contacts the patient""s cervix with the cervical agent in the intended manner.
In another alternative embodiment, a collapsible support structure surrounds the exterior of the cervical cap to further define and hold the cervical cap""s shape. The support structure is collapsible in order to fit within an applicator. In the preferred embodiment, the support structure comprises a plurality of flexible fingers that define the concave shape of a cervix and a cervical cap. In alternative embodiments, the support structure is a flexible rim on the edge of the cervical cap.
In another embodiment, the cylindrical structure, the cervical cap, the support structure surrounding the cervical cap, or any combination thereof may incorporate one or more other therapeutic agents. Therefore, when deployed within a patient, these additional therapeutic agents may leech out in a well known manner and provide further treatment to the patient. For example, the cylindrical structure may contain a neutralizing agent that neutralizes the effects of a therapeutic agent on the internal surface of the cervical cap and protects the areas around the cervix, e.g., the vulva, that are not to receive treatment with the therapeutic agent. This is an important feature especially when the therapeutic agent is an anti-viral agent.
There are many advantages associated with the cervical agent delivery apparatus and system of the present invention. The apparatus ensures the direct application and delivery of a therapeutic agent to a patient""s cervix. By having an absorbent cylindrical structure which absorbs any excess therapeutic agent, the patient""s vagina and vulva are protected from undesired exposure to the therapeutic agent. The low-tech nature of the apparatus and its conventional deployment ensures that practically anyone can deploy the apparatus with success. As a result, health care costs are minimized because the apparatus may be used by patients at home. Lastly, a patient can receive multiple types of treatment with a single use of the apparatus when the apparatus incorporates two or more therapeutic agents.